Hikaru1337

So I have a Kona Ute I got sometime around 2011, and last year I installed a BionX motor on it. While I love what this bike can do, my rear innertube doesn't seem so happy with the arrangement. My rear innertube has failed twice in the last month, and once only a few months prior. As far as I can tell, going up and down curbs seems to be what ultimately caused the failure the last couple times. Does anyone know if there's a particularly robust kind of innertube I could throw on the back wheel that would hold up to the heavier stresses I'm putting on the back wheel? Or is there some trick to managing tire pressure for heavier bikes that I'm unaware of? The bike itself is 55lbs and I try to keep the pressure between 50 and 60 PSI, and the max pressure listed on the tire is 75PSI. I've checked the inside of the tire, and the inside of the wheel itself where the innertube rests, and couldn't find anything that could cause an issue with the innertube.

Any advice is appreciated! Thanks.

FiftySix

Where is the failure on your tubes happening?

Maybe go to thick thorn resistant tubes if you haven't already?

https://bicyclewarehouse.com/collect...-various-sizes

https://bicyclewarehouse.com/collect...sta-valve-tube

Hikaru1337

The last three times the hole has been in different places actually. The most recent break was on the inner portion of the innertube that rests against the wheel. the last couple before that were on the portion that's up against the inner side of the tire.

I'll have to check out those thicker walled innertubes you linked and see how they hold up.

FiftySix

There were no holes through the tire on the last couple flats?

Hikaru1337

Nope! My tires were getting old, so even though I couldn't find anything wrong with them aside from worn tread, I replaced them after the second of the 3 recent flats, but the same kind of riding still got me another flat.

FiftySix

I really don't have experience with utility bikes with electric motors. I do hope the thicker tubes work for you, Hikaru!

StephenH

I don't see the term in here, but commonly called a pinch flat. One solution, don't go up and down curbs.
That can happen with any tire/tube/rider if you hit a sharp edge wrong, it's not just you.
Oftentimes, you'll get two little cuts in the tube, not one.
I don't know that thicker tubes will solve that, either.

burnthesheep

Sounds like a pinch flat to me. My suggestions are:

-If you want same comfort and add durability, go up a tire size. More volume but at a similar pressure in the bigger tire you likely won't pinch flat as much. Otherwise, you'll just have to add pressure to avoid the pinch flats.

-Comort, speed, and durability.......that bike's specs online say it is a 700c. They DO sell latex tubes for cyclocross bikes that are 700c. I think they should work in a tire from 32 to 40ish in size. Latex is slightly less prone to pinch flats. If worried about thorns, just buy a type with the removable valve core and pour in some sealant to the tube. It's a utility bike, not a racer, but latex can still provide added comfort and durability despite its fragile reputation.

MikeyMK

I got inner tubes 3-4 times the weight of bicycle ones for my tandem. They're thicker than the tyre, could almost use them without tyres...

I'd looked up moped tubes and I think they're for the front wheel of a Honda C90 or alike.

That's bearing in mind my rims are 50-559 and tyres are 60-559.